‘Cast iron’ is different from ‘Pig iron' because :

1.	Cast iron is obtained by melting pig iron and coke using a hot air blast.
2.	Cast iron contains lower amount of carbon (3%) than pig iron.
3.	Unlike pig iron, cast iron is extremely hard and brittle.
4.	All of the above

The correct statement among the following is:

Copper matte is put in silica lined converter to :

The role of cryolite in the metallurgy of aluminium is :

Leaching of low-grade copper ores does not involve

1. Cu getting converted into Cu²⁺(aq) in acidic medium

2. Cu getting converted into Cu²⁺(aq) in basic medium

3. Cu²⁺(aq) getting reduced to Cu

4. using bacteria in the presence of air.

Zinc cannot be extracted from zinc oxide via CO reduction because:

(Given:  Ellingham diagram)

 

The value of ∆_fG^O for the formation of ${\mathrm{Cr}}_2{\mathrm{O}}_3$ is – 540 kJmol⁻¹and that of Al₂O₃  is – 827 kJ mol⁻¹. The correct statement is-

1. Cr can reduce Al₂O₃ to Al

2. Cr₂O₃ cannot reduce Al₂O₃ to Al

3. Al can reduce ${\mathrm{Cr}}_2{\mathrm{O}}_3$ to Cr

4. Al cannot reduce ${\mathrm{Cr}}_2{\mathrm{O}}_3$ to Cr

The better reducing agent for ZnO is: 

1. C

2. CO

3. CO₂

4. ${\mathrm{CO}}_3^{2-}$

The process in which Cl₂ is obtained as a by-product is :

Al can reduce MgO under the following conditions:

1. Above 500 °C, Al can reduce MgO

2. Below 500 °C, Al can reduce MgO

3. Below 1350 °C, Al can reduce MgO

4. Above 1350 °C, Al can reduce MgO